qemu-img: ocssd.img: Unknown file format 'ocssd'

[sinashan]

Hello,
I'm trying to do a university course project using open-channel ssd. As I don't have a physical ocssd, I'm trying to configure a virtual one using qemu. After configuring and installing required things now I'm getting into this error after running the code
qemu-img create -f ocssd -o num_grp=2,num_pu=4,num_chk=60 ocssd.img
Error is:
qemu-img: ocssd.img: Unknown file format 'ocssd'
As I'm a total newbie, I would appreciate any help or guide on how to deal with this problem.
Thank you

[birkelund]

Could it be that the qemu-img you are running belongs to a system installed qemu? That is, it is picking up /usr/bin/qemu-img instead of, say, /usr/local/bin/qemu-img. Try running it directly from the source tree (i.e. ./x86_64-softmmu/qemu-img ...).